We can't do it ______ your help. [ ]
A. with
B. of
C. under
D. without
答案：D
口形红细胞于扫描电镜下，根据红细胞的内凹程度可分为()
A．单向凹陷，呈盘形
B．双面凹陷，呈面包圈状
C．双面凹陷，呈圆盘状
D．单向凹陷较深，似面盆或蘑菇帽状
E．单向凹陷更深，似杯状或深臼状
* * 复战丹功效与作用
